Q&A with Mike Laidley, vice president of Orbital ATK’s Next Generation Launch program (members only)

Rain showers and gloomy clouds blew through NASA’s Kennedy Space Center on Monday evening, but it was high winds that prevented liftoff of a SpaceX Falcon 9 rocket early Tuesday with a commercial communications satellite. Launch has been rescheduled for Thursday at 1:35 a.m. EDT (0535 GMT).

The stacking of a United Launch Alliance Atlas 5 rocket this week at Cape Canaveral signals the start of a busy six-week campaign to ready ULA’s trusty workhorse launcher for its debut in a new human-rated configuration in mid-December.

SpaceX’s fired the engines of its Falcon Heavy rocket at launch pad 39A at 12:30 p.m. EST (1730 GMT) on Wednesday. The crucial pre-launch engine test has been repeatedly delayed since the rocket returned to the launch pad earlier this month.